422.2 📚 國考版醫垫國考 / PGY OSCE

422.2.0.1 📌 Cram Sheet

422.2.0.1.1 🔥 高 yield 15
  1. Ca homeostasis: PTH + 1,25-Vit D + FGF-23
  2. PTH effects: bone resorption ↑ + renal Ca reabsorb ↑ + 1α-OH ↑ + P excretion ↑
  3. Vit D activation: skin/diet → liver 25-OH → kidney 1α-OH (PTH-stim) → 1,25-D
  4. 25-D = storage marker; 1,25-D = active (kidney activation)
  5. FGF-23: P excretion + 1,25-D inhibitor
  6. Osteoporosis: T-score ≀ -2.5 OR fragility fracture
  7. Bisphosphonate 1st line: alendronate, risedronate, ibandronate, zoledronic acid
  8. Denosumab: anti-RANK-L Q6mo SC
  9. Teriparatide / abaloparatide: PTH analog anabolic Q1d × 2 yr
  10. Romosozumab: anti-sclerostin 12 monthly doses (22E; CV caveat)
  11. Sequential: anabolic → anti-resorptive (severe)
  12. Denosumab 急停 rebound — must bridge to bisphosphonate
  13. Glucocorticoid = #1 secondary cause osteoporosis
  14. Paget’s: ALP ↑↑↑ + zoledronic acid
  15. CKD-MBD: phosphate binder + activated Vit D + cinacalcet
422.2.0.1.2 🔢 必背
項目 æ•žå­—
Total Ca normal 8.5-10.5 mg/dL
Ionized Ca normal 4.4-5.2 mg/dL
Phosphate normal 2.5-4.5 mg/dL
25-D deficiency < 20 ng/mL
25-D insufficient 21-29
25-D sufficient 30-100
T-score osteoporosis ≀ -2.5
T-score osteopenia -1 to -2.5
Calcium daily intake 1200 mg
Vit D daily 800-2000 IU
Albumin Ca correction + 0.8 × (4 − albumin)
Bisphosphonate holiday oral 5 yr
Bisphosphonate holiday IV 3 yr
Denosumab dosing Q6 mo SC
Teriparatide duration 2 yr lifetime
Romosozumab duration 12 monthly doses

422.2.0.2 ⭐ 高 yield

422.2.0.2.1 Bone Cells Quick
Cell Function Marker
Osteoblast Build bone Bone-ALP, P1NP
Osteocyte Mature, mechanosensor, sclerostin —
Osteoclast Resorb bone CTX, NTX, TRAP
422.2.0.2.2 Bone Drug by Mechanism
Drug Mechanism
Alendronate, risedronate, ibandronate, zoledronic acid Bisphosphonate (osteoclast apoptosis)
Denosumab Anti-RANK-L (block osteoclast formation)
Teriparatide (PTH 1-34) Anabolic (intermittent PTH stim osteoblast)
Abaloparatide (PTHrP analog) Anabolic
Romosozumab Anti-sclerostin (anabolic + anti-resorptive)
Raloxifene SERM (bone agonist + breast antagonist)
Calcitonin Anti-resorptive (limited efficacy)
Strontium ranelate Anabolic + anti-resorptive (limited use due to CV risk)
422.2.0.2.3 Osteoporosis Causes
  • Primary: postmenopausal (Type 1), senile (Type 2)
  • Secondary:
    • Glucocorticoid (#1)
    • Hypogonadism, hyperthyroid, hyperPTH
    • Vit D def
    • CKD
    • Celiac, IBD, bariatric
    • MM, leukemia
    • Anorexia, FHA
    • PPI, SSRI, aromatase inhibitor, GnRH agonist, anticonvulsant, heparin
    • Smoking, alcohol
422.2.0.2.4 Vit D Causes Deficiency
  • Insufficient sunlight
  • Diet
  • Malabsorption (celiac, IBD, bariatric)
  • CKD (1α-OH ↓)
  • Liver disease (25-OH ↓)
  • Drugs: phenytoin, rifampin, anti-retroviral
  • Obesity (sequestration)
  • Granulomatous: 1,25-D ↑↑↑ → hyperCa (paradox)
422.2.0.2.5 Paget’s Disease
  • ↑ disorganized bone remodeling
  • Skull, spine, pelvis, long bones
  • ALP ↑↑↑ specific marker
  • Treatment: zoledronic acid IV (very effective)
  • Bone scan + targeted X-ray
422.2.0.2.6 Renal Osteodystrophy (CKD-MBD)
  • CKD → P retention + 1,25-D ↓
  • → 2° hyperparathyroidism → 3°
  • High-turnover (osteitis fibrosa) vs low-turnover (adynamic) vs mixed
  • Treatment: P binder, activated Vit D, cinacalcet, surgery for refractory

422.2.0.3 🎯 自我檢枬

  1. PTH 4 effects? → Bone resorb + Ca reabsorb + 1α-OH + P excrete
  2. 25-D vs 1,25-D? → 25-D storage; 1,25-D active
  3. FGF-23? → P excrete + 1,25-D inhibitor
  4. Osteoporosis T-score? → ≀ -2.5
  5. Calcium daily? → 1200 mg
  6. Vit D deficiency? → < 20 ng/mL
  7. Albumin Ca correction? → + 0.8 × (4 − albumin)
  8. Bisphosphonate 1st? → Alendronate weekly
  9. Denosumab dosing? → Q6 mo SC
  10. Teriparatide duration? → 2 yr lifetime
  11. Romosozumab duration? → 12 monthly doses
  12. Glucocorticoid + osteoporosis? → #1 secondary
  13. Paget’s marker? → ALP ↑↑↑
  14. Paget’s drug? → Zoledronic acid
  15. CKD-MBD treatment? → P binder + active Vit D + cinacalcet
  16. Denosumab急停? → Rebound fracture; bridge bisphosphonate

⚠ AI 草皿。